IME, book theft was a much bigger concern back in the days before PDFs and Amazon dominated the market. For example, back in the 1980s, my high school library had a huge Dragon Magazine collection, but culled them due to the number of issues that were never returned. In the 1990's the Boston Public Library had several of its RPG books (mostly D&D 4E) chronically listed as "Overdue/Lost."

However, my current local library system (in Lexington, KY) has been slowly growing their RPG collection since I moved here 4 years ago. One branch has offered the D&D 5E PHB and the Pathfinder, CoC (7E?), and Savage Worlds core rules for some time now, and very recently added Fate Core, GURPS 4E, Fantasy AGE, Fiasco, and most of the other D&D 5E core books and hardcover adventures. I'm actually planning to stop in sometime this week to check out a few of them!